The aim of this research is to examine the maturational changes that occur in cultured epidermal and oral keratinocytes as they transit from the basal layer to the surface. We seek to learn how these changes are controlled in normal and pathologically altered epithelia. In the next year our experiments will focus upon three aspects of epithelial metabolism: 1. The regulation of keratin synthesis and tonofilament assembly in cultured keratinocytes from oral dysplastic and neoplastic lesions. 2. The fractionation of normal keratinocytes based upon their maturational age and an analysis of keratin biosynthesis in these fractions. 3. The effect of adenovirus infection upon the metabolism of cultured epidermal keratinocytes.